www.ti.com
1
2
3
4
8
7
6
5
SHUTDOWN
BYPASS
IN+
IN-
V
O
-
GND
V
DD
V
O
+
D OR DGN PACKAGE
(TOP VIEW)
DESCRIPTION
Audio
Input
Bias
Control
V
DD
350 mW
6
5
7
V
O
+
V
DD
1
2
4
BYPASS
IN -
V
DD
/2
C
I
R
I
C
S
1
F
C
B
0.1
F
R
F
SHUTDOWN
V
O
-
8
GND
From System Control
3
IN+
-
+
-
+
TPA321
SLOS312C JUNE 2000 REVISED JUNE 2004
350-mW MONO AUDIO POWER AMPLIFIER WITH DIFFERENTIAL INPUTS
Fully Specified for 3.3-V and 5-V Operation
Wide Power Supply Compatibility
2.5 V 5.5 V
Output Power for R
L
= 8
350 mW at V
DD
= 5 V
250 mW at V
DD
= 3.3 V
Ultralow Supply Current in Shutdown
Mode . . . 0.15 A
Thermal and Short-Circuit Protection
Surface-Mount Packaging
SOIC
PowerPADTM MSOP
The TPA321 is a bridge-tied load (BTL) audio power amplifier developed especially for low-voltage applications
where internal speakers are required. Operating with a 3.3-V supply, the TPA321 can deliver 250 mW of
continuous power into a BTL 8-
load at less than 1% THD+N throughout voice band frequencies. Although this
device is characterized out to 20 kHz, its operation was optimized for narrower band applications such as cellular
communications. The BTL configuration eliminates the need for external coupling capacitors on the output in
most applications, which is particularly important for small battery-powered equipment. This device features a
shutdown mode for power-sensitive applications with a quiescent current of 0.15 A during shutdown. The
TPA321 is available in an 8-pin SOIC surface-mount package and the surface-mount PowerPADTM MSOP, which
reduces board space by 50% and height by 40%.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PowerPAD is a trademark of Texas Instruments.
PRODUCTION DATA information is current as of publication date.
Copyright 20002004, Texas Instruments Incorporated
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
www.ti.com
ABSOLUTE MAXIMUM RATINGS
DISSIPATION RATING TABLE
RECOMMENDED OPERATING CONDITIONS
TPA321
SLOS312C JUNE 2000 REVISED JUNE 2004
This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated
circuits be handled with appropriate precautions. Failure to observe proper handling and installation
procedures can cause damage.
ESD damage can range from subtle performance degradation to complete device failure. Precision
integrated circuits may be more susceptible to damage because very small parametric changes could
cause the device not to meet its published specifications.
AVAILABLE OPTIONS
PACKAGED DEVICES
MSOP
T
A
SYMBOLIZATION
SMALL OUTLINE
(1)
(D)
MSOP
(1)
(DGN)
40
C to 85
C
TPA321D
TPA321DGN
AJB
(1)
The D and DGN packages are available taped and reeled. To order a taped and reeled part, add the
suffix R to the part number (e.g., TPA321DR).
over operating free-air temperature range (unless otherwise noted)
(1)
UNIT
V
DD
Supply voltage
6 V
V
I
Input voltage
0.3 V to V
DD
+0.3 V
Continuous total power dissipation
Internally limited (see Dissipation Rating Table)
T
A
Operating free-air temperature range
40
C to 85
C
T
J
Operating junction temperature range
40
C to 150
C
T
stg
Storage temperature range
65
C to 150
C
Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds
260
C
(1)
Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings
only, and functional operation of the device at these or any other conditions beyond those indicated under "recommended operating
conditions" is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
PACKAGE
T
A
25
C
DERATING FACTOR
T
A
= 70
C
T
A
= 85
C
D
725 mW
5.8 mW/
C
464 mW
377 mW
DGN
2.14 W
(1)
17.1 mW/
C
1.37 W
1.11 W
(1)
See the Texas Instruments document, PowerPAD Thermally Enhanced Package Application Report
(literature number SLMA002), for more information on the PowerPADTM package. The thermal data
was measured on a PCB layout based on the information in the section entitled Texas Instruments
Recommended Board for PowerPAD on page 33 of the before mentioned document.
MIN
MAX
UNIT
V
DD
Supply voltage
2.5
5.5
V
V
IH
High-level voltage
SHUTDOWN
0.9 V
DD
V
V
IL
Low-level voltage
SHUTDOWN
0.1 V
DD
V
T
A
Operating free-air temperature
40
85
C
2
www.ti.com
ELECTRICAL CHARACTERISTICS
OPERATING CHARACTERISTICS
ELECTRICAL CHARACTERISTICS
OPERATING CHARACTERISTICS
TPA321
SLOS312C JUNE 2000 REVISED JUNE 2004
at specified free-air temperature, V
DD
= 3.3 V, T
A
= 25
C (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
|V
OO
|
Output offset voltage (measured differentially)
SHUTDOWN = 0 V, R
L
= 8
, R
F
= 10 k
5
20
mV
PSRR
Power supply rejection ratio
V
DD
= 3.2 V to 3.4 V
85
dB
I
DD
Supply current (see Figure 3)
SHUTDOWN = 0 V, R
F
= 10 k
0.7
1.5
mA
I
DD(SD)
Supply current, shutdown mode (see Figure 4)
SHUTDOWN = V
DD
, R
F
= 10 k
0.15
5
A
|I
IH
|
High-level input current
SHUTDOWN, V
DD
= 3.3 V, V
I
= 3.3 V
1
A
|I
IL
|
Low-level input current
SHUTDOWN, V
DD
= 3.3 V, V
I
= 0 V
1
A
V
DD
= 3.3 V, T
A
= 25
C, R
L
= 8
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
P
O
Output power
(1)
THD = 0.5%,
See Figure 9
250
mW
P
O
= 250 mW,
f = 20 Hz to 4 kHz,
THD + N
Total harmonic distortion plus noise
1.3%
A
V
= -2 V/V,
See Figure 7
Maximum output power bandwidth
A
V
= -2 V/V, THD = 3%, See Figure 7
10
kHz
B
1
Unity-gain bandwidth
Open loop,
See Figure 15
1.4
MHz
Supply ripple rejection ratio
f = 1 kHz, C
B
= 1 F, See Figure 2
71
dB
A
V
= 1 V/V,
C
B
= 0.1 F,
V
n
Noise output voltage
15
V(rms)
R
L
= 32
,
See Figure 19
(1)
Output power is measured at the output terminals of the device at f = 1 kHz.
at specified free-air temperature, V
DD
= 5 V, T
A
= 25
C (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
|V
OO
|
Output offset voltage (measured differentially)
SHUTDOWN = 0 V, R
L
= 8
, R
F
= 10 k
5
20
mV
PSRR
Power supply rejection ratio
V
DD
= 4.9 V to 5.1 V
78
dB
I
DD
Supply current (see Figure 3)
SHUTDOWN = 0 V, R
F
= 10 k
0.7
1.5
mA
I
DD(SD)
Supply current, shutdown mode (see Figure 4)
SHUTDOWN = V
DD
, R
F
= 10 k
0.15
5
A
|I
IH
|
High-level input current
SHUTDOWN, V
DD
= 5.5 V, V
I
= V
DD
1
A
|I
IL
|
Low-level input current
SHUTDOWN, V
DD
= 5.5 V, V
I
= 0 V
1
A
V
DD
= 5 V, T
A
= 25
C, R
L
= 8
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
P
O
Output power
THD = 0.5%,
See Figure 13
700
mW
P
O
= 350 mW,
f = 20 Hz to 4 kHz, See
THD + N
Total harmonic distortion plus noise
1%
A
V
= 2 V/V,
Figure 11
Maximum output power bandwidth
A
V
= 2 V/V, THD = 2%, See Figure 11
10
kHz
B
1
Unity-gain bandwidth
Open loop,
See Figure 16
1.4
MHz
Supply ripple rejection ratio
f = 1 kHz, C
B
= 1 F, See Figure 2
65
dB
A
V
= -1 V/V,
C
B
= 0.1 F,
V
n
Noise output voltage
15
V(rms)
R
L
= 32
,
See Figure 20
3
www.ti.com
PARAMETER MEASUREMENT INFORMATION
Audio
Input
Bias
Control
V
DD
6
5
7
V
O
+
V
DD
1
2
4
BYPASS
IN -
V
DD
/2
C
I
R
I
C
S
1
F
C
B
0.1
F
R
F
SHUTDOWN
V
O
-
8
R
L = 8
GND
3
IN+
-
+
-
+
TPA321
SLOS312C JUNE 2000 REVISED JUNE 2004
Terminal Functions
TERMINAL
I/O
DESCRIPTION
NAME
NO.
BYPASS is the tap to the voltage divider for internal mid-supply bias. This terminal should be connected
BYPASS
2
I
to a 0.1-F to 1-F capacitor when used as an audio amplifier.
GND
7
GND is the ground connection.
IN-
4
I
IN- is the inverting input. IN- is typically used as the audio input terminal.
IN+
3
I
IN+ is the noninverting input. IN+ is typically tied to the BYPASS terminal for SE operations.
SHUTDOWN
1
I
SHUTDOWN places the entire device in shutdown mode when held high (I
DD
~ 0.15 A).
V
DD
6
V
DD
is the supply voltage terminal.
V
O
+
5
O
V
O
+ is the positive BTL output.
V
O
-
8
O
V
O
- is the negative BTL output.
Figure 1. Test Circuit
4
www.ti.com
TYPICAL CHARACTERISTICS
-50
-60
-80
-100
20
100
1 k
-30
-20
f - Frequency - Hz
0
10 k 20 k
-10
-40
-70
-90
V
DD
= 5 V
V
DD
= 3.3 V
R
L
= 8
C
B
= 1
F
k
SVR
- Supply V
oltage Rejection Ratio - dB
V
DD
- Supply Voltage - V
1.1
0.7
0.3
-0.1
0.9
0.5
0.1
3
4
6
2
5
I DD
- Supply Current - mA
SHUTDOWN = 0 V
R
F
= 10 k
TPA321
SLOS312C JUNE 2000 REVISED JUNE 2004
Table of Graphs
FIGURE
k
SVR
Supply voltage rejection ratio
vs Frequency
2
I
DD
Supply current
vs Supply voltage
3, 4
vs Supply voltage
5
P
O
Output power
vs Load resistance
6
vs Frequency
7, 8, 11, 12
THD+N
Total harmonic distortion plus noise
vs Output power
9, 10, 13, 14
Open-loop gain and phase
vs Frequency
15, 16
Closed-loop gain and phase
vs Frequency
17, 18
V
n
Output noise voltage
vs Frequency
19, 20
P
D
Power dissipation
vs Output power
21, 22
SUPPLY VOLTAGE REJECTION RATIO
SUPPLY CURRENT
vs
vs
FREQUENCY
SUPPLY VOLTAGE
Figure 2.
Figure 3.
5
PDF 
ZIP